Role of Cell-Mediated Enzymatic Degradation and Cytoskeletal Tension on Dynamic Changes in the Rheology of the Pericellular Region Prior to Human Mesenchymal Stem Cell Motility.

Human mesenchymal stem cells (hMSCs) are encapsulated in synthetic matrix metalloproteinase (MMP) degradable poly(ethylene glycol)-peptide hydrogels to characterize cell-mediated degradation of the pericellular region using multiple particle tracking microrheology. The hydrogel scaffold is degraded by cell-secreted enzymes and cytoskeletal tension. We determine that cell-secreted enzymatic degradation is the main contributor to changes in the pericellular region, with cytoskeletal tension playing a minimal role.

Monitoring solid oxide CO2 capture sorbents in action.

The separation, capture, and storage of CO2 , the major greenhouse gas, from industrial gas streams has received considerable attention in recent years because of concerns about environmental effects of increasing CO2 concentration in the atmosphere. An emerging area of research utilizes reversible CO2 sorbents to increase conversion and rate of forward reactions for equilibrium-controlled reactions (sorption-enhanced reactions). Little fundamental information, however, is known about the nature of the sorbent surface sites, sorbent surface-CO2 complexes, and the CO2 adsorption/desorption mechanisms.